A particular type of human/machine interface is termed a graphical user interface, and basically is constituted by software resident in a computing device that translates instructions or data to visual information to be displayed on a visual display device.
One simple form of graphical user interface is text-based and utilises cursor control to enable navigation about a screen, however the predominant trend in known graphical user interfaces is the use of "windowing" systems that operate by `point and click` actions by the user. Examples of windowing software systems are Apple QUICKDRAW, Microsoft WINDOWS and XWINDOWS created by MIT. Often windowing interfaces also incorporate the earlier form of cursor control, giving the user some form of flexibility in operation of the computing device, particularly with respect to data input. The icons and windowing structures presented to the user do not, however, provide access to the galaxy of commands and operations, so it is always necessary for the user to resort to operation of the keys of a conventional qwerty keyboard. There thus is the need for the user to learn and remember the qwerty keyboard layout.
Other examples of human/machine interfaces can be obtained from the text "Cognitive Aspects of Visual Languages & Visual Interfaces", edited by M. J. Tauber et al, published by North-Holland, Amsterdam, 1994.
Conventional user input devices such as keyboards, mouses and track balls require a benign and stable environment since the user must exhibit fine nervous system motor control in the use of the fingers. Mobile environments do not lend themselves to such fine movements, and can make operation of computing devices impracticable or even impossible.
The present invention is directed to overcoming or at least ameliorating one or more of the disadvantages noted above. Alternatively, or additionally, it can also be said to provide a useful alternative to known human/machine interfaces.
The present invention is directed to a human/machine interface that operates on the principle of `what you see is what you press`, and therefore removes the need for the user to be familiar with operational commands or the qwerty keyboard layout, rather maps input keystrokes directly from the display to the input device.
The human/machine interface of the present invention is particularly suited to use: (a) underwater, where there is a restricted range of human movement; (b) in a terrestrial mobile environment, (i.e. particularly `wearable computers` and in vehicle-borne situations) where high levels of motion make it difficult for the user to operate a computing device via an input device; and (c) in airborne environments, where there are again high levels of motion acting on the user of the computing device.
It is convenient now to define some of the terminology that is used throughout the specification.
The fingers and thumb of the human hand are referred to as "digits". The term "digits" also embraces toes.
A "key" is to be understood as an input transducer operated by a single digit, and can include a pushbutton, switch, force transducer or the like. An "input device" typically can have four keys, one for each of the fingers, and one or more "keys" for the thumb, given that the thumb has greater dexterity than the fingers. Even so, there can be any number of keys in the range 1 to 5. The activation/operation of one or a combination of the keys at the same time is referred to as a "chord". A "couplet" is two consecutive chords, or two simultaneous chords performed by the left and right hand.
A "display device" is to be understood a hardware element such as a video monitor or liquid crystal display. The display device thus presents the viewer with an image that, for convenience, will be termed a "display".
A display visually presents "indicia". An indicium is presented in a manner that represents one or more keys. A number of indicia in close spatial or sequential arrangement is termed a "panel". Each panel overlays a number of notional non-overlapping sequential regions. In that sense the regions can also be thought of as partitioning a portion of the display. An indicium can span over one or more regions in the sense that it is oriented substantially orthogonally to the regions. An indicium itself can be either contiguous or discontiguous. An indicium also is referred to as a "button".